         ^String seqs (:seq aln)
         ^String quals (.qual aln)
         [seqs-at-ref quals-at-ref] (into []
-                                         (index-transducer
+                                         (two-vec-transducer
                                           (index-to-seq-qual seqs quals))
                                          idx)]
     (assoc aln

  [^long start ^long end alns]
  (seq-step start end 0 alns))

(defn- index-to-seq-qual
  [^String seqs ^String quals]
  (let [empty-qual? (and (= (.length quals) 1)

            [(int (* 0.8 q1)) 0]
            [0 (int (* 0.8 q2))]))))))

(defn- correct-pair-quals
  "Correct quals of a pair. Returns a map with corrected quals."
  [^SAMAlignment a1 ^SAMAlignment a2]
